Method of wokking the pawl in parallel vises



J. JOHNSON.

Parallel Vice.

No. 7,262. I Patented April 9, 1850.

N. PETERS Fholmllnhagmpben Wash nglan. 04 c.

m orrion.

JASPER JOHNSON, GENESEO, NEW YORK.

METHOD OF WGRKI NG THE PAWL IN PARALLEL VISES.

Specification of Letters Patent No. 7,262, dated April 9, 1850.

T 0 all whom it may concern Be it known that I, JASPER- JOHNSON, of Geneseo, in the county of Livlngsto-n and State of New York, have invented a new and i the upper ends of which the upper ends of the crossed levers a, a, are secured by joint pins: the levers ct, a, are united at their centers by a fulcrum oint, and the ears 6, i, at their lower extremities play freely in the lower portions of the grooves 7a, 7a,- in which grooves they (the ears 5, 11,) are retained by the plates j, j, that areconfined to the inner sides of the vise bars and project over the edges of the said grooves.

7 Near the lower end of the movable vise bar A, one end of the rack bar 6, is confined, which passes thence rearward through a mortise in the stationary bar A. A pawl 0, is located at the lower end of the groove in the bar A, which has a spring leg cl, de secnding from its fulcrum pin, that bears against the bottom of the groove andelevates the extremity teeth of the rack e.

b, is a metallic plate, the upper end of which is secured near the upper end of the groove in A, and its lower end bears against the front side of the pawl 0: when the screw g, is turned, the jointed levers a, a, will cause of the pawl above the.

the bar A, asit moves out and in, to retain a position parallel to the stationary bar A; and when any pressure is exerted upon any substance placed in the jaws of the vise, the inward movement that will thereby be imparted to the lower end of A, will throw the lower ends of both the levers a, a, to the rear, and thus cause one of them to bear against the plate I), and force the pawl 0, down upon the teeth of the rock 6; by which means a very slight movement of the lower end of A, will actuate the pawl 0, and cause it to firmly hold the lower end of the movable vise bar (A,) and prevent any injurious strain from being exerted upon the jointed levers and the screw.

Having thus fully described my improvement in parallel vises, I would observe that I do not claim the placing the crossed ointed levers a, a, bet-ween the parallel vise bars A, A, nor the rack e, made fast to the lower portion of the movable bar A, and extend ing thence through a mortise in the stationary bar A, as these have been made use of before; but

What I do claim as my invention and desire to secure by Letters Patent, is-

The within described combination of the spring pawl o, and the metallic plate (or lever) b, with the foot of one of the crossed levers a, by which the spring pawl is made to act upon and retain the rack bar 6, when any article is grasped between the jaws of" the vise, substantially as herein set forth.

The above specification signed and witnessed this 28th day of September 1849.

JASPER JOHNSON. WVitnesses:

I. H. VAIL,

WV. H. KELsEY. 

